Engine starter control



Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE clerson,-Ind., assignors to General Motors Cor- .po'ratioh, Detroit, Mich., a corporation of Dela- Application May 9, 1951, Serial No.-225,426

' 9 Claims. 1

v This invention relates to engine starter control apparatus by 'whichan engine cranking electric motor is caused to operate by closing a manually controlled switch and by which operation of the motor is-prevented while the engine is self operative.

An object of the invention is to provide improved means whereby operation of the starting motor is prevented while the engine is self operative. In the disclosed embodiment of the present invention, this object is accomplished by the use of a switch which is normally closed in order that the starting motor circuit will be completed by closure of a-manually operated switch. This normally closed switch remains closed during engine cranking and is opened in response to self-operation of the engine and remains open so long as the engine is self-operative. The opening of the normally closed switch is effected by engine suction responsive means which operates in opposition to two springs which are in assisting relation during engine cranking so that engine crankin suction is insufficient to open the switch. When the engine is self-operative, engine suction becomes sufficient to overcome these springs and the normally closed switch is opened and the operation of the starting motor ceases. So long as this engine remains selfoperative, even though engine suction may decrease substantially as when operating at full load and wide open throttle, this switch does not close because, during movement of the movable contact of this switch toward switch closing posi-' tion, the two springs are caused to act differentially so that a decrease in suction to a value lower than occurring at any time during selfoperation of the engine must take place before this switch will close.

Further objects and advantages of the present invention will be apparent from the following description reference being made to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 includes a wiring diagram of the present invention and a longitudinal sectional view of a suction operated, normally closed switch.

Fig. 2 is a sectional view on line 2-2 of Fig. 1.

In Fig. 1 an electric starting motor 26 grounded at 2| has a field winding 280. connected by a wire 22 to a fixed contact 23 of a switch 2d. The switch 24 has a movable contact 25 and is adaptedto be moved into engagement with fixed contacts 23 and 26. The movable contact is urged from the fixed contacts 23, 25 by a spring 21. The fixed contact 23 isconnected'bya wire 2Bwith the storage battery 29 grounded at 30.

The switch 24 is closed by an electromagnetic means comprising an armature 3| surroundedby a winding 33 of fewer turns of relatively coarse wire and 'a winding 32 of large numbers of turns of fine wire. One end of winding 32 is grounded at 32a and the other end of said winding 32is connected with one end of Winding connected with the wire 22. The energization of coils and 33 to effect closure of switch 24 requires manual closure of an ignition switch 35 having a movable contact 38 and closure of a manually controlled switch 36 having a movable contact 42. When these switches are closed the following circuit is established: battery 29, wire 28 wire 39, contact 38, terminal ill, wire ll, contact 42, terminal 43, wire M coil 45 of relay 46, wire 41, wire 48, generator 50 and ground. Coil 45 having been energized, movable contact 52 engages-fixed contact 54 of relay Q8 and thefollowing circuit is established: battery 29, wire 28, wire 53, contacts 52 and 54, wire 55, a normally closed switch 30 to be described, wire 58, coil 32 to ground 32a, coil 33, w ire22, field coil 2012,5131;-

ing mo'tor 2'0 and grounds 2i and 3B. Coils 32 and 33 having beenenergi'zed, switch 24 closes and 'the starting motor operates. While the engine is being cranked, the switch remains closed and the engine becomes self-operative,

the switch 633 opens and remainsopen so long as the engine remains self-operative.

7 While the engine is self-operative it drives the generator 159 to charge the battery 29, the cut-out relay 5| closing automatically to complete the charging circuit. The current in field winding Fof the generator 59 is controlled by a voltage regulator VR.

Thesuction operated switch 60 includes a cupshaped housing 6! having its open end closed by a nonconducting switch back Bla which supports rivets'62 and 53 presenting contact surfaces exposed within the housing 6|. Rivets 62 and B3 are connected respectively with conducting plates 64 and 65 which are mechanically and electrically connected with terminal .posts 56 and 51 respectively. The contact surfaces of rivets 62 and '63 are normally bridged by the flexible contact arms 59a of a movable contact 59. The other end of the housing Si is closed with the exception of an opening formed in a boss Bib provided by the closed end. The boss Gib ex tends through an opening in a shell 56 and "the closed end of the housing ti is secured to the shell 66 by suitable means, not shown, forek- 3 ample rivets or spot welding. A diaphragm chamber is enclosed by shells 66 and 6? between the peripheral flanges of which a diaphragm 68 is clamped.

A supporting member 70 has a central projection provided with an opening in alignment with a central opening in the shell 67. The member 10 and shell 67 are secured together by a bushing II which also retains screws 72 the heads of which are clamped between member 10 and shell 61. Screws 12 provide the means for attaching the switch 60 to a suitable bracket, not shown.

A plug 15 is threaded in the bushing H. A seal washer I6 is disposed between the plug 75 and bushing H to form a fluid tight joint. The plug 15 provides a partition H having a small opening 18 through which engine suction is com municated to the diaphragm 68. The plug 15 is threaded at 19 to receive a coupling by which a pipe, not shown, connected with the engine in- I take manifold is attached to the plug.

A cup-shaped washer 30 which receives one end of a compression spring 8|, diaphragm 6B and a washer 63 are fixed to a contact carrier rod 82 by riveting over the reduced left end portion of the latter. Rod 82 provides a bulbous, cam portion 85 and is supported for axial movement by the back 6| a which provides a recess 9| for receiving the rod portion 66. Blade 59 is insulatingly supported upon rod 82 by nonconducting washers 88 and 89 which are clamped between a shoulder 81 of the rod 82 and a washer 96 secured by staking the rod at 90a.

The closed end of the housing 6| supports a 'U-shaped spring member 92 made of relatively stiff wire and comprising a yoke 93 and parallel arms 94. The spring 92 is attached by clips 95 secured to the closed end of the housing. The arms 94 of the spring 92 are bowed and they straddle the carrier 82 with the highest point of the arched portions of arms 84 engageable by the cam 85.

The operation of the switch 60 is as follows: When the engine is not running the parts are in their normal position shown in Fig. 1 with the contact arms 59a of blade 59 in engagement with the stationary contacts 62 and 63. As stated before, the starting motor operates to crank the engine in response to closure of ignition switch 35 and a second manually controlled switch 36. During engine cranking, the engine suction is insuflicient to cause the amount of diaphragm movement to the left in Fig. 1 required to separate blade 59 from contacts 62 and 63 because the left movement of the diaphragm is resisted by the combined action of springs 8! and 92. As the carrier rod begins moving to the left the cam portion 85 engages the bowed portions of the arms 94 tending to decrease the bow in these arms and to spread them apart. Resistance of spring 92 increases while the resistance of spring 3| increases while blade contacts 59a still remain in engagement with contacts 62 and 63 because contacts 59a are biased by blades 59 against the contacts 62 and 63. Thus the springs BI and 92 act cumulatively to prevent opening of switch 60 during engine cranking altho cranking suction might be a substantial amount.

When the engine becomes self-operative, engine intake suction communicated to the left side of the diaphrgam in Fig. 1 overcomes the resistance of spirngs 8i and 92 and spreads the arms 94 so far apart that the high point of cam 85 passes between the arms 94. Then arms 94 press upon the right frusto-conical portion of cam to provide a force assisting engine suction to move the carrier 82 with a snap action to separate the contacts 59a of blade 59 from the stationary contacts 62, 63, in order to open the circuit to coils 32 and 33 whereupon the springs 21 move contact 25 from stationary contacts 23, 26 to open the starting motor circuit. Because diaphragm movement is opposed by springs 8| and 92 before switch 66 is opened, relatively high engine suction, for example 10" Hg, is required to open this switch.

So long as the engine is self-operative, the engine intake vacuum does not fall to such low value as to result in movement of the cam 85 to the right of arms 94. This cannot occur until intake vacuum has dropped to a very low value, 1" Hg for example; and such low value does not occur while the engine is self-operative even on full load and wide open throttle. The withholding of closure of switch 60 is brought about because, during movement of the carrier 82 toward the right in Fig. 1, spring 8 I is opposed by spring 92 acting on the right frusto-conical face of cam 85. When engine suction falls as low as 1" Hg for example, spring 8| is able to overcome spring 92 and close switch 60.

The switch 36 may be a manually operated switch located on the instrument panel or it may be a neutral safety switch under control by a transmission selecting lever not shown.

When the engine is propelling the vehicle, the switch 36 is open. Therefore coil 45 of relay 46 is deenergized. If the switch 36 is moved to closed position while the engine is running the starting switch 24 cannot be closed because the suction device 31 maintains the separation of contacts 59, 62, 63.

The cranking motor is caused to operate by closing the ignition switch 35 provided the switch 36 is closed. If the engine stops while the switch 36 is open and the transmission is in one of its driving positions with the ignition switch 35 turned to On position, the engine is started merely by moving the transmission selecting lever to Neutral position and closing the switch 36.

The present invention can be used on a vehicle having a standard or manually operated gear shift. In such case the switch 36 could be a manually operated dash switch. I

The present invention can be used with a starting motor which is connected with the engine by a starter drive which is actuated by the armature 3! of switch 24 or by a starter drive of the automatic screw-pinion type. If the screw pinion drive is used, it is desirable in case of a false start, to allow the starting motor to come to rest before closing switch 36 to cause the starting motor to operate.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In an engine starting system the combination comprising, an electric starting motor; a current source; and means for efiecting connection of said source and the motor, said means including a normally closed switch having spaced fixed contacts, a carrier having a bridging contact mounted thereon, said bridging contact adapted to be held normally in engagement with said fixed contacts; a suction device including a diaphragm connected with said carrier, said diaphragm having one side subjected to atmosphere and having the other side responsive to engine suction; -a first spring means resisting movement of "the diaphragm for switch opening; asecond spring means; and means operating in response tomovement of the contact carrier in adirection for contact separation for conditioning said second spring means for assisting the first spring means in opposing the diaphragm movement and operating in response to movement of said carrier in said direction for-contact closing for conditioning said second spring means for opposing said-first spring means.

2. In an engineistarting system the combination comprising an "electric motor, a current source, and means for effecting connection or said source and the motor and including .a normally closed electric switch ,having fixed contacts and a movable contactor for engaging said fixed contacts; a carrierior said movable contactor; cam means supported bysaid carrier; a :suction device including a flexible diaphragm connectedwith-said carrier, said diaphragm actu- 1ated 'by'the operation of the engine to move said ,carrierto separatesaid contactor'from saidfixed contacts; a compression spring for resisting movement of saiddiaphragm forswitch opening; yieldable means cooperating with said cam means in response to movement of said carrier in a direction for switch opening for assisting said spring in opposing the diaphragm movement up to the time of switch'opening, and operating in response to movement of said carrier in the direction for switch closing to provide resistance for opposing said force of said spring to close said switch.

3. In an engine starting system the combination comprising; an electric starting motor; a current source; and means for efiecting connection of said source and the motor, said means including a normally closed switch having fixed contacts and a contact member having resilient arms engaging the fixed contacts; a reciprocable carrier associated with said contact member; cam means carried by said carrier; a suction device including a diaphragm connected with said carrier, said diaphragm actuated by the operation of the engine to move said carrier to separate said contact member from said fixed contacts; a coiled spring resisting movement of said diaphragm for switch opening; a resilient U- shaped member fixed relative to said carrier and having its arms straddling said carrier, each arm having a bowed portion, said cam means operating in response to movement of said carrier in a direction for contact separation for decreasing said bowed portions of said arms and increasing said resistance of said arms for assisting said coil spring in opposing the diaphragm movement, said cam means spreading said arms and cooperating therewith to snap said contact member out of engagement with said fixed contacts, said arms cooperating with said cam means in response to movement of said contact carrier in said direction for contact closing for conditioning said arms of said U-shaped member for opposing said coiled spring.

4. In an engine starting system the combination comprising, an electric starting motor; a current source; and means for eiiecting connection of said source and the motor, said means including a normally closed switch having fixed contacts and a movable contact member having flexible arms engaging said fixed contacts; a reciprocable carrier associated with said movable contact, cam means carried by said carrier; a

: suction 7. device including a diaphragm connected with said carrier, said diaphragm actuated by the operation of the engine to move said carrier contact .closing' to provide resistance for :opposing the force exerted by said coil spring.

5. In :an engine starting system the combination comprising, an electric starting motor, a

urrent source; :and-means for effecting connection of said source andthe motor, said-'meansineluding a :normally closed switch having fixed contacts and a movable-contact member having resilient arms engaging said fixed contacts; a

reciprocable carrier for said movable contact member; cam means carried by said carrier; "a suction device including a flexible diaphragm connected with said carrier, said diaphragm actuated by the operation of the engine to move said carrier to separate said'arms from said fixed contacts; a coiled spring resisting movement of said diaphragm for :switchopening; a U-shaped spring member having its bight and portions of its arms fixed but having the free ends of the arms straddling the carrier, said free portions of said arms cooperating with the cam means to snap said resilient contact arms out of engage ment with said fixed contacts on movement of said carrier in one direction and to snap said resilient contact arms into engagement with said fixed contacts on movement of said carrier in the opposite direction.

6. In an engine starting system the combination comprising, an electric starting motor, a current source, and means for completing a circuit from said source to the motor and including a normally closed switch, said switch including spaced fixed contacts and a movable member for bridging the contacts, a first spring means and a second spring means for holding the switch in closed position, both spring means assisting each other in resisting the opening of the switch, suction means associated with said movable member of the switch operable through suction produced by the engine when it starts for overcoming the resistance of said second spring means to allow said movable member to open the switch to the motor; said movable member having cam means which engages said second spring means when said movable member is moved to open position so as to assist said first spring in resisting the opening of the switch and said cam means also engaging said second spring means to hold said movable member in switch open position as long as the engine is self-operative.

'7. In an engine starting system the combination comprising, an electric starting motor, a current source, and means for effecting connection of said source and the motor, said means including a normally closed switch having a contact member, a reciprocable supporting rod movable to position the contact member to disconnect the circuit to the motor, vacuum operated means actuate-d by the operation of the engine for moving said rod to shift said contact member to open the motor circuit, said vacuum means including a flexible diaphragm connected to said rod, a first spring means for yieldingly pressing said diaphragm, said rod, and said contact plate in a direction to close the switch, a second spring means, and cam means associated with said rod, said cam means cooperating with said second spring means for maintaining said switch closed until the engine starts whereupon said suction device moves said cam means to a position wherein said cam means cooperates with said second spring means to prevent movement of said rod to a position to close said switch while the engine is running.

8. In an engine starting system the combina tion comprising, an electric starting motor, a current source, and means for completing a circuit from said source to the motor and including a normally closed switch, means responsive to self operation of the engine for opening said switch, two springs normally effectively cumulatively to oppose operation of said means to open said switch, and means operated by said responsive means for conditioning one of the springs, after the switch is opened, for action in opposition to the other spring.

9. In an engine starting system the combination comprising, an electric starting motor, a current source, and means for completin a circuit from said source to the motor and including a normally closed switch having fixed and movable contacts, a carrier supporting said movable contact and movable in a direction normal to the face of said fixed contact, one of said contacts being resilient whereby a certain movement of said carrier in a direction to separate said contacts precedes separation of said contacts, means responsive to self-operation of the engine to move said carrier in the direction for contact separation, a spring for opposing the contact-separating movement of said carrier, a second spring and means operated by said carrier for conditioning said second spring to assist said first spring as said carrier moves in the direction for contact separation and for conditioning said second spring for opposition to said first spring after said contacts have been separated.

PAUL L. SCHNEIDER.

HAROLD J. CROMWELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,067,613 Lane July 15, 1913 1,790,564 Williams Jan. 27, 1931 1,924,633 Whittington et a1. Aug. 29, 1933 1,984,736 Garoutte Dec. 18, 1934 2,067,084 Hartzell Jan. 5, 1937 2,075,305 Sayre Mar. 30, 1937 2,105,643 Dyer Jan. 18, 1938 2,151,400 Williams Mar. 21, 1939 2,170,240 Fitch Aug. 22, 1939 2,289,463 Schlosser July 14, 1942 2,497,462 McCracken Feb. 14, 1950 2,497,948 Lincoln Feb. 21, 1950 FOREIGN PATENTS Number Country Date 770,607 France July 2, 1934 

